Jim O'Brien came off the bench to earn Barnsley their first away point of the season and deny Mick McCarthy victory on his one-year anniversary as Ipswich Town boss.
Daryl Murphy had headed the Tractor Boys into a half-time advantage, but O'Brien's introduction just prior to the break inspired the Reds to snatch a share of the spoils from an entertaining clash in Suffolk.
Aaron Cresswell's set pieces proved to be the biggest source of goalscoring chances in a first half that was dominated by Ipswich following a quiet opening quarter-of-an-hour.
The left-back's delivery found Luke Chambers in the centre of the goal, but the former Nottingham Forest centre-back headed over the crossbar from eight yards.
Murphy was more accurate with his nodded effort, though, as he shook off his marker and met Cresswell's 41st-minute corner at the far post to put the hosts ahead.
An injury to Jacob Mellis forced Barnsley manager David Flitcroft to turn to his bench, and his decision to bring on O'Brien helped the Tykes completely turn the momentum of the tie in their favour.
The Scottish winger was on hand at the back post to net the visitors' equaliser on 70 minutes, applying a side-footed finish after Tommy Smith could only partially clear Paddy McCourt's cross.
From then on, the Reds applied constant pressure and appeared the more likely team to grab a winner, with O'Brien and Jason Scotland going close in two of their 11 second-half efforts on Dean Gerken's goal.
Former Ipswich striker Scotland ruffled the side-netting after he had been allowed too much space to chest down and then unleash a half-volley from O'Brien's free kick.
Barnsley were nearly caught out on the counter-attack, though, when Jay Tabb's deflected shot was parried by Jack Butland, with the rebound just evading the outstretched foot of Frank Nouble.
Nouble nearly had a decisive impact on the game again in stoppage time, when he went down in the box under the challenge of Jean Yves Mvoto, but referee Andy D'Urso did not award a penalty.
Cresswell was sent off for his protests after the final whistle had blown on the 1-1 draw that extends Barnsley's unbeaten run to three games, with Ipswich now winless in five Championship matches.
